Make null gpu context threadsafe(r) and make sure buffer objects are destroyed.

Make null gpu context threadsafe(r) and make sure buffer objects are destroyed.

NOTREECHECKS=true

Committed: https://skia.googlesource.com/skia/+/776d355147307357e47cc65d51706a4231ff95b5

[bsalomon, 2014-08-14 13:51:27]

This fixes up some valgrind issues on with dm --abandonGpuContext. The abandoned
buffer objects' memory was never freed. Also adds some thread safety when
accessing global null context state.

[robertphillips, 2014-08-14 14:10:17]

lgtm + dox request & nits

https://codereview.chromium.org/470993002/diff/40001/src/gpu/gl/GrGLCreateNul...
File src/gpu/gl/GrGLCreateNullInterface.cpp (right):

https://codereview.chromium.org/470993002/diff/40001/src/gpu/gl/GrGLCreateNul...
src/gpu/gl/GrGLCreateNullInterface.cpp:46: 
// This class maintains a sparsely populated array of buffer pointers. Free
slots
// in the array are threaded by keeping the index of the first free slot in
'fFreeListHead'
// and each subsequent slot as an int stored in the pointer's space.

?

https://codereview.chromium.org/470993002/diff/40001/src/gpu/gl/GrGLCreateNul...
src/gpu/gl/GrGLCreateNullInterface.cpp:103: static const int kFreeListEnd = -1;
Line these two up ?

https://codereview.chromium.org/470993002/diff/40001/src/gpu/gl/GrGLCreateNul...
src/gpu/gl/GrGLCreateNullInterface.cpp:117: 
fBufferMgr ?

https://codereview.chromium.org/470993002/diff/40001/src/gpu/gl/GrGLCreateNul...
src/gpu/gl/GrGLCreateNullInterface.cpp:118: BufferManager fBuffers;
Line these guys up with fBuffers ?

[bsalomon, 2014-08-14 14:52:09]

https://codereview.chromium.org/470993002/diff/40001/src/gpu/gl/GrGLCreateNul...
File src/gpu/gl/GrGLCreateNullInterface.cpp (right):

https://codereview.chromium.org/470993002/diff/40001/src/gpu/gl/GrGLCreateNul...
src/gpu/gl/GrGLCreateNullInterface.cpp:46: 
On 2014/08/14 14:10:17, robertphillips wrote:
> // This class maintains a sparsely populated array of buffer pointers. Free
> slots
> // in the array are threaded by keeping the index of the first free slot in
> 'fFreeListHead'
> // and each subsequent slot as an int stored in the pointer's space.
> 
> ?

Acknowledged.

https://codereview.chromium.org/470993002/diff/40001/src/gpu/gl/GrGLCreateNul...
src/gpu/gl/GrGLCreateNullInterface.cpp:103: static const int kFreeListEnd = -1;
On 2014/08/14 14:10:17, robertphillips wrote:
> Line these two up ?

Done.

https://codereview.chromium.org/470993002/diff/40001/src/gpu/gl/GrGLCreateNul...
src/gpu/gl/GrGLCreateNullInterface.cpp:117: 
On 2014/08/14 14:10:17, robertphillips wrote:
> fBufferMgr ?

Done.

https://codereview.chromium.org/470993002/diff/40001/src/gpu/gl/GrGLCreateNul...
src/gpu/gl/GrGLCreateNullInterface.cpp:118: BufferManager fBuffers;
On 2014/08/14 14:10:17, robertphillips wrote:
> Line these guys up with fBuffers ?

Done.

[bsalomon, 2014-08-14 14:52:42]

The CQ bit was checked by bsalomon@google.com

[commit-bot: I haz the power, 2014-08-14 14:53:47]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/bsalomon@google.com/470993002/60001

[bsalomon, 2014-08-14 15:04:55]

The CQ bit was checked by bsalomon@google.com

[commit-bot: I haz the power, 2014-08-14 15:05:57]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/bsalomon@google.com/470993002/100001

[commit-bot: I haz the power, 2014-08-14 15:13:32]

Committed patchset #6 (100001) as 776d355147307357e47cc65d51706a4231ff95b5